Fungicides

ABSTRACT

This invention relates to a new fungicidally active compound of formula (I), a method of combating fungi at a locus infested or liable to be infested therewith, and an agricultural composition where X is H or O − A +  and A is a radical (II).

This is a 371 of PCT/EP00/09360 filed Sep. 15, 2000, now WO01/21626.

This invention relates to a new compound having fungicidal activity.

In one aspect, the invention provides a compound of formula I

where X is hydrogen or O⁻A⁺ and A is a radical

The two compounds resulting aredimethyl-[3-(propoxycarbonylamino)propyl]-ammonium phosphate anddimethyl-[3-(propoxycarbonylamino)propyl]ammonium phosphite.

The compounds of the invention have activity as fungicides, especiallyagainst Phycomycete diseases of plants. e.g. vine downy mildew(Plasmopara viticola), various Phytophthora blights e.g. late tomato orpotato blight (Phytophthora infestans), Pythium spp., Aphanomyces spp.,Bremia spp., Perenospora spp. and Pseudoperenospora spp.

The invention thus also provides a method of combating fungi at a locusinfested or liable to be infested therewith, which comprises applying tothe locus the compounds of the invention.

The invention also provides an agricultural composition comprising thecompounds of the invention in admixture with an agriculturallyacceptable diluent or carrier.

The composition can comprise one or more additional active ingredients,for example compounds known to possess plant-growth regulant,herbicidal, fungicidal, insecticidal or acaricidal properties.Alternatively the compound of the invention can be used in sequence withthe other active ingredient.

Fungicides with which the compound can be mixed include acylanilines,such as metalaxyl, oxadixyl, ofurace, benalaxyl and furalaxyl;cymoxanil; mancozeb; chlorothalonil; folpet; captan; famoxadone;fenamidone; spiroxamine; fluazinam; dimethomorph; strobilurins, such askresoxim-methyl, azoxystrobin and trifloxystrobin, pyrimethanil,cyprodinil; mepanipyrim; and iprodione.

The names quoted for these compounds are the non-proprietary commonnames and the chemical structure can be found for example by referenceto the “Pesticide Manual”, eleventh edition, 1997, published by theBritish Crop Protection Council. Of the compounds whose common names arenot mentioned in the Pesticide Manual the full chemical names are asfollows:

trifloxystrobin—methyl(E,E)-methoxyimino-{2-[1-(3-trifluoromethylphenyl)-ethylideneaminooxymethyl]phenyl}acetate

spiroxamine—8-tert-butyl-1,4-dioxaspiro[4.5]decan-2-ylmethyl(ethyl)-(propyl)amine

fenamidone—(S)-1-anilino-4-methyl-2-methylthio-4-phenylimidazolin-5-one

The composition of the invention may include for example a dispersingagent, emulsifying agent or wetting agent. Usually they are in the formof an aqueous concentrate.

The concentration of the active ingredient in the composition of thepresent invention, as applied to plants is preferably within the rangeof 0.0001 to 1.0 per cent by weight, especially 0.0001 to 0.01 per centby weight. In a primary composition, the amount of active ingredient canvary widely and can be, for example, from 5 to 95 per cent by weight ofthe composition.

In the method of the invention the compound is generally applied toseeds, plants or their habitat. Thus, the compound can be applieddirectly to the soil before, at or after drilling so that the presenceof active compound in the soil can control the growth of fungi which mayattack seeds. When the soil is treated directly the active compound canbe applied in any manner which allows it to be intimately mixed with thesoil such as by spraying, by broadcasting a solid form of granules, orby applying the active ingredient at the same time as drilling byinserting it in the same drill as the seeds. A suitable application rateis within the range of from 5 to 1000 g per hectare, more preferablyfrom 10 to 500 g per hectare.

Alternatively the active compound can be applied directly to the plantby, for example, spraying or dusting either at the time when the fungushas begun to appear on the plant or before the appearance of fungus as aprotective measure. In both such cases the preferred mode of applicationis by foliar spraying. It is generally important to obtain good controlof fungi in the early stages of plant growth as this is the time whenthe plant can be most severely damaged. The spray or dust canconveniently contain a pre- or post-emergence herbicide if this isthought necessary. Sometimes, it is practicable to treat the roots of aplant before or during planting, for example, by dipping the roots in asuitable liquid or solid composition. When the active compound isapplied directly to the plant a suitable rate of application is from0.025 to 5 kg per hectare, preferably from 0.05 to 1 kg per hectare.

The compounds of formula I may be obtained by reacting an amine offormula II

with phosphoric or phosphorous acid. In general it is desirable to reactan acid addition of salt of the compound of formula II, e.g. thehydrochloride, with a salt of the phosphorus acid, e.g. an alkali metalsalt, such as the sodium salt.

This reaction can be carried out in aqueous solution

The invention is illustrated in the following Example.

EXAMPLE 1

A solution of sodium phosphate dodecahydrate (8.8 g in water (75 ml))was added to an aqueous solution ofpropyl-3-(dimethylamino)propylcarbamate hydrochloride (20 ml ofconcentration 776.9 g/l) in a further 75 ml of water. The mixture wasstirred for 30 min, evaporated to dryness, dissolved in dichloromethane(200 ml) and the insoluble white solid (sodium chloride) filtered off.The filtrate was evaporated to leavedimethyl-[3-(propoxycarbonylamino)propyl]ammonium phosphate, as aviscous colorless oil.

Nmr spectroscopy confirmed that the product was a salt by observation ofthe chemical shifts relative to propyl 3-(dimethylamino)propylcarbamate.

EXAMPLE 2

A solution of phosphorous acid (2.87 g in water (50 ml)) was stirred for1 hour with a solution of sodium hydroxide (2.8 g in water (50 ml)).Propyl 3-(dimethyiamino)propylcarbamate hydrochloride (15.7 g) in water(50 ml) was added and the mixture stirred for 30 min, evaporated todryness, dichloromethane (450 ml) added and re-evaporated. The residuewas dissolved in dichloromethane (150 ml) allowed to stand for 1 hourand the insoluble white solid (sodium chloride) filtered off. Thefiltrate was evaporated to leavedimethyl-[3-(propoxycarbonylamino)propyl]ammonium phosphite, as aviscous colorless oil.

Nmr spectroscopy confirmed that the product was a salt by observation ofthe chemical shifts relative to propyl 3-(dimethylamino)propylcarbamate.

What is claimed is:
 1. A compound of formula I

where X is hydrogen or O⁻A⁺ and A is a radical